基于天线消除的非线性自干扰消除全双工通信

摘要

由于无线全双工系统中存在严重的自干扰问题,天线消除技术能够从模拟域的角度消除部分线性自干扰,考虑发射机功率放大器(power amplifier,PA)产生的非线性影响,提出一种基于天线消除的非线性数字自干扰消除方案.将PA和非线性自干扰信道均描述为并行哈默斯坦(parallel Hammerstein,PH),通过估计模型系数和重建干扰对消信号,在数字域消除残留干扰.仿真结果表明,该方案与线性数字自干扰消除相比能实现更多的消除数量,运用同一种非线性数字消除技术,带有天线消除的全双工系统与无天线消除相比能够实现更高的信干噪比(signal to interference plus noise ratio,SINR).%In the wireless full duplex system with inevitable self-interference, an antenna cancellation technique is able to mitigate part of linear self-interference in the analog domain.Considering the nonlinear effects induced by transmitter's power amplifier (PA), a nonlinear digital self-interference cancellation algorithm based on antenna cancellation was proposed.Power amplifier and nonlinear self-interference channel were modeled as parallel Hammerstein (PH) nonlinearity.By estimating the model's parameters and reconstructing the destructive signal, the nonlinear residual self-interference signal was eliminated in the digital domain.Results of simulation demonstrate that the proposed algorithm outperforms the linear digital self-interference cancellation in terms of the amount of achieved cancelation.And using the same nonlinear digital cancellation technique, the full duplex system with antenna cancellation can obtain a higher signal to interference plus noise ratio (SINR).